psp doesnt always turn on and freezes when i use it

so i got kinda weird problem. about 3 months ago i was playing psp in hot and wet day and it turned off by itself. then it started to act weird. it didn't turn on always, only green light appeared. if i managed to turn it just freezed after a while in XMB and i couldn't get it working. after a day it wasn't even possible to turn it on no more. so i thought my psp is useful and wasn't using it anymore. but yesterday i tried again to turn it on and everything was working. i even managed to install 3.52 M33 firmware. ok so next day i am copying some files in my memory stick and psp freezes again and it all starts over. at this moment i cant turn psp on. so people what do u think wheres the problem. i dunno maybe theres some problem in motherboard or maybe psp is overheating? so what should i do?

use key cleaner,Basically, KeyCleaner is a PSP application that enables you to see the state of the IdStorage on your PSP. It also allows for dumping keys when necessary and fixes certain problems caused by old downgraders
hope this help